I’ve written a few times about my experimentation this training cycle with glycogen depletion (GD) runs to teach my body to tap into fat for fuel. Without having run my marathon yet, the jury is still out on the results. However, I’ve learned plenty new about how much and what type of fueling my body prefers from this trial and error.
I think in total, I did about six or seven GD runs. After the first couple, and as my runs became longer, I did them on an alternating weekly basis. My shortest (the first) was a 16-miler, and my longest was a 20. Truthfully, I never really intended to get up to a 20 without fuel, but decided that week to just give it a try. I surprised myself by feeling good enough to make it through without fuel that day.
So what have I learned? That I used to eat too much before and during long runs. I guess I was always afraid of bonking, but I discovered that I actually feel better on
less fuel. The long runs where I ate as much as I used to and then fueled as often as I used to were not my best runs (a couple were downright crappy, in fact). My best long runs this training cycle were those in a glycogen depleted state, or when I ate far less than I did in the past.
I also learned that coffee is my new favorite training partner. Again, fear of the outcome (ahem, the literal outcome) prevented me from ever trying coffee before a long run. When Mark Cucuzzella recommended I try it before a GD run, however, I gave it a go. Now I know that it provides me with loads of fuel for a long run. I think it also allows me to stay strong on less fuel both before and during my runs. So marathon day, I will have a cup of coffee, something I’ve never done in a long race before.
The bottom line–I’m very happy I tried GD long runs. They are going to be my mainstay from now on, with the exception of the really long ones and those closest to marathon dates so that I can keep my system accustomed to gels for race days.
Do you have your long-run fueling perfected or are you still working on it?